1. Field of the Invention
The present invention relates to the field of still video imaging, and especially to a compact still video camera of the type that separately records both fields of a still video frame.
2. Description Relative to the Prior Art
A still video recording standard has been established in which a small, flexible magnetic disk is used to store up to 50 still video pictures. The recording format provides the option of storing a full frame (two circular tracks per picture) for 25 pictures, or a single field (one circular track per picture) for 50 pictures. According to this standard, a radial reference position is defined in relation to the disk by providing a small metal insert (referred to as the PG yoke) in a hub that supports the disk for rotation. The location of this insert is sensed continuously as the disk is rotated and a so-called PG pulse or signal is accordingly derived. The leading edge of the vertical synchronizing signal is then positioned seven horizontal lines (.+-. two lines) from the reference position, i.e., from the occurrence of the PG signal. In addition, for full frame recording, the PG signal serves as a reference for head switching. The standard calls for the rotation of the disk at 3600 r.p.m.; head switching, therefore, occurs at the field rate.
A stereo recording ordinarily depends on separately recording two displaced images corresponding to left and right eye perspective views. For example, in U.S. Pat. No. 4,523,226 two images from separate cameras are recorded on "left" and "right" reels of video tape. The video tapes are initially produced and later played back on recorders that are interlocked since synchronization between the left and right images is critical for quality stereo reproduction. Because such techniques employ specialized equipment and non-standard recording formats, a stereo system is ordinarily incompatible with existing non-stereo equipment. Besides adding manufacturing cost due to specialized components, it is difficult to market an expensive, incompatible format. There is a need, therefore, for a stereo system that couples into an existing video format without resort to highly specialized processing systems.